Railway signaling.



lH. W. GRIFFIN.

RAILWAY SIGNALING.

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@NIT-ED STATES PATENT FIFIQE.

HENRY W. GRIFFIN, OF NEW YORK, N. Y., ASSIGNOR T THE UNION 'SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY SIGNALING.

Specification of Letters Patent.

Patented Jian. 2,1917.

Original application filed January 27, 1913, Serial No. 744,367. Divided and this appIication filed .Tune 30,

1913, Serial No. 776,483.

To all whom t may concern.'

Be it known that I, HENRY WV. GRIFFIN,

a citizen of the United States, residing at New York city, 1n the county and State of New York, have invented certain new vand useful Improvements in Railwayy Sig- 27, lfll, Serial No. 744,367, for railway signaling.

I will describe two forms of railway sig.

naling embodying my invention and will then point out the novel features thereof in claims. f

In the accompanying drawings, Figure l Vis a diagrammatic view showing a stretch of single track having applied thereto one form of railway signaling embodying my invention. Fig. 2 is a view' similar to Fig. l, but showing a modification of the signaling shown in Fig. 1.

Similar reference characters refer to similar parts in each of the several views.

Referring lirst to Fig. 1, A designates the track rails of a stretch of single track over which traflic moves in both directions.

The track rails of the stretch A arerelectrically separated from the adjoining track rails by insulations 27. The stretch A is provided with a track circuit comprising the track rails, a source of current connected with the track rails adjacent the middle of the stretch, and two track relays It and R connected with thetrack rails adjacent the ends of the stretch respecalternating signaling current, whichl Renewed October 19, 1916.A Serial No. 126,626.

are preferably of a type responsive only to alternating current; as here shown, these relays are each of the vane type. YVit-h the track circuit arranged as just described, it is well understood that when a car or train enters the stretch from either end, it immediately opens the track relay adjacent that end, but the track relay adjacent the other end is not opened until the car or train reaches a point near the point of connection of the source of signaling current with the track rails, as indicated on the drawing. After the car or train has passed a short distance beyond the point of connection of the source of signaling current with the track rails, the relay in the rear of the car or train again closes, but the other relay remains open until the car or train leaves the stretch. rlhe point at which the relay in the rear of the car or train closes is substantially the same as the point at which this relay is opened by a car or train moving in the other direction.

Traffic into the stretch A from opposite directions is governed by two end signals S and S, located respectively adjacent the ends of the stretch. I also provide two intermediate signals B and B for the stretch A. Signal B is located in advance of signal S, but in the rear of the point at which an eastbound car or train causes track relay R to open; and, similarly, signal B is located in advance of signal S but in the rear of the point at which a westbound car or train passing through the stretch causes track relay It to open. As here shown, the distance of intermediate signals B and B from the adjacent end of the stretch is. about one-quarter of the distance from the adjacent end of the stretch to the middle, although I do not wish to limit myself to this particular location of these intermediate signals. Each of the four signals is adapted to indicate stop and proceed, as shown in Fig. l,

all four of the signals are of the semaphore type, but vit is understood that other types of signals may equally well be employed.

Each ot the end signals S and S is controlled by both track relays R and R;

intermediate signal B is controlled by track relay R and intermediate signal B is controlled by track relay R. I will now explain the circuits by which this control of the signals is accomplished. Track relay R controls a signal circuit which comprises two branches for the control respectively of signal S and signal B. lIhe circuit for signal B is from source of current 11 (here shown as being a direct current battery),

through contact 12 of relay It', wires 13 The operation of the apparatus shown inY Fig. 1 is as follows: Assume that a caror train passes through the stretch A 'from .west to east. As this car or train enters the stretch, it immediately opens track relay R, thereby causing signals S, B and S to change to stop indication. The opening or' relay R does not, however, effect signal B and this latter signal continues to indicate proceed until after it has been passed by the car or train. When the car or train reaches the point near the middle of the stretch, as indicated on the drawing, it

l causes track relay R to open and the openvpassage of a westbound ing of this relay causes signal B to change to stop indication. When the car or train reaches a point a short distance beyond the middle of the stretch, that is, substantially the point at which a westbound car or train opens relay R, track relay R closes, so that signal B then changes to proceed indication. Track relay R, however, remains open until the car or train leaves the stretch, consequently, signals S, S and B, continue to indicate stop until the car or train leaves the stretch.

The operation of the apparatus for the car or train through the stretch is similar to that just explained. If two cars or trains moving in oppositeV directions should enter the stretch A at the same time, it is obvious that each car or train would receive a proceed indication at signals S and S respectively, hence both cars or trains would be authorized to proceed into the stretch. Both signals B and B would, however, be changed at once to indicate stop, hence, both cars or trains would receive a stop indication as they approach these signals. It will be seen, therefore, that it is impossible to bring two cars ortrains together in the stretch A.

Each intermediate signal B, B is preferably locatedV a considerable distance in the rear of the point at which a car or train proceeding through the stretch from the adjacent end causes the track relay at the opposite end of the stretch to open. This location of the intermediate signals is preferable for several reasons; rst, so that the distance between each end signal and the adjacent intermediate signal can be made uniform for both long and short blocks; second, so that a car or train will not be required to back up too far in case it finds the intermediate signal indicating stop v; third, so that, the distance between thepend signals and the adjacent intermediate signals being short, when a car or train approaches an intermediate signal the driver will not be under the impression that he is approaching a new block section.

Referring now to Fig. 2,' the apparatus and circuits'here shown are similar to those shown in Fig. 1. In Fig. 2, however, the intermediate signals, which are here designated by the reference Ycharacters C and C, respectively, are of the light type instead of the semaphore type. Each intermediate signal C and C comprises two electric lamps r and g. These lamps are provided with lenses or glasses of dierent colors. For example, each lamp 7' may be provided with a red lens'or glass, and each lamp g may lie/provided with a green lens or glass.

In accordance with the usual practice, when the red lamp r of either of these signals is illuminated and the green extinguished, the

signal indicates stop, and when the green Y lamp is illuminated andV the red extinguished the signal indicates proceed `Each signal C and C is controlled by a signal relay D or D', the controlV of each of these signals being such that when the corresponding signal relay is energized, the green lamp g is illuminated and the red lamp 1 is extinguished, but'when the corresponding signal relay is denergized the red lamp rk is illuminated and the green` Y lamp g is extinguished. The circuit for the green lamp g of signal C is from battery 28, through the front point or` contact 29 of relayV I), wire 30, lamp g, wire 31, common wire O to battery 28; the circuit for red lamp r of signal C. is from battery 28, through the back .point of contact 29 of relay B, wire 32, lamp r, wire 31, common wire O to battery 28. The circuits for the lamps r and g ofsignal C are similar to those just traced for signal C.

Track relay R controls a signal circuit v which isV provided with 1- two branches for the control respectively of signal relay VD and signal S; and track relay VR similarly controls a signal circuit Vwhich, is provided with two branches for the control respec-V tively of signal relay D and signal S. The operation of the apparatus shown in Fig. 2 will be evident from the explanation given hereinbefore of the operation oli'the apparatus shown in Fig. l.

Although I have herein shown and described only two forms or' railway signaling embodying my invention, it is understood that various changes and modilications may be made therein within the scope of the appended claims, without departing from the spirit and scope of my invention.

Having thus described my invention, what ,l claim is:

1. ln combination, a stretch of railway track, a source of alternating signaling current connected with the track rails adjacent the middle of the stretch, two track relays connected with the track rails adjacent the ends of the stretch respectively, two end signals located adjacent the ends of the stretch respectively, two intermediate signals located respectively in advance oi' the end signals but in the rear of the point at which a car or train passing through the stretch from the adjacent end opens the track relay at the other end, two signal circuits one controlled by each track relay, each signal circuit comprisingtwo branches tor the control respectively ol the two signals on the opposite side of the source from the track relay, the said branch for each end signal being controlled also by the track relav adjacent the corresponding end.

2. In combination, astretch of railway track, a source of signaling current connected with the track rails adjacent the middle of the stretch, two track relays connected with the track rails adjacent the ends of the stretch respectively, two end signals for the stretch located adjacent the ends of the stretch respectively, two intermediate signals located respectively on opposite sides of the source, two signal circuits one controlled by each track relay, each signal circuit comprising two branches for the control respectively of the two signals on the opposite side of the source from the track relay, the said branch for each end signal being controlled also by the track relay adjacent the corresponding end.

3. 1n combination, a stretch of railway track, two track relays connected with the track rails adjacent the opposite ends of the stretch and arranged to be opened successively by a car or train passing through the stretch, the relay iirst opened remaining open until after the other relay has opened, means for energizing said relays, two end signals located respectively adjacent the ends of the stretch, two intermediate signals located respectively in advance of the end signals but in the rear of the point at which a car or train passing through the stretch from said end causes the track relay at the opposite end of the stretch to open, and two signal circuits one controlled by each track relay, each signal circuit comprising two branches for the control respectively oit' the two signals adjacent the opposite end of the stretch from the track relay which controls the signal circuit, the branch for each end signal being controlled also by the track relay adjacent such end signal.

a. ln combination, a stretch of railway track, two track relays connected with the track rails adj acent the opposite ends ol the stretch and arranged to be opened successively by a car or train passing through the stretch, the relay first opened remaining open until after the other relay has opened, means for energizing said relays, two end signals located respectively adjacent the ends of the said stretch for governing the entrance of cars or train into the stretch, two intermediate signals located respectively in advance of the end signals but in the rear of the point at which a car or train passing through the stretch from said end causes the track relay at the opposite end of the stretch to open, a signal relay for each intermediate signal for the control thereof, two signal circuits one controlled by each track relay, each signal circuit comprising two branches for the control respectively of the end signal at the opposite end of the stretch from the track relay and of the signal relay for the intermediate signal adjacent the opposite end of the stretch from the track relay, the said branch for each end signal being controlled also by the track relay adjacent such end signal.

5. In combination, a stretch of single track over which traffic moves in both directions, two track relays connected with the track rails adjacent the ends of the stretch respectively and arranged to be opened successively by a car or train passing through the stretch, the relay first opened remaining open until after the other relay has opened, means for energizing said relays, two end signals located respectively adjacent the ends of the stretch, two intermediate signals located respectively in advance of the end signals but in the rear of the point at which a car or train passing through the stretch from said end causes the track relay at the opposite end of the stretch to open, each intermediate signal comprising two electric lamps adapted when illuminated to indicate respectively stop and proceed, a signal relay for each intermediate signal, circuits for the lamps of each signal controlled by the corresponding signal relay and so arranged that when the relay is energized the proceed lamp is illuminated and that when the signal relay is denergized the stop lamp is illuminated, and means for controlling eachen@ In testimony whereofl alix my signature signal and the signal-I relay forthe adjacent in presence oftvvr.Witne'sse's'.V

intermediatesignal by the track relay at the n Y HENRY W. GRIFFIN. oppositey enel of' the stretch and for eontrol- VVitnesses: Y

5 ling each end? signal alsol by the adjacent A. M. LINDEN'STRUT'H,

track rela-y. RBT. B: KAY. 

